today, I encountered a problem with NSURLConnection. I want to download the contents of the URL http://api.wunderground.com/api/fs3a45dsa345/geolookup/q/34.532900,-122.345.json. If I simply paste the URL into Safari, I get the correct response. However, if I do the same thing with NSURLConnection, I get a "not found" response. Here's the code I'm using:

It turns out the web service request is failing because the User-Agent header doesn't get set by default. To set it, use an instance of NSMutableURLRequest rather than NSURLRequest to create the request, as shown below:

Where is the delegate code? For async NSURLConnection there needs to be a delegate method to receive the returned data. Other options include sendSynchronousRequest: or if it must be async wrapping sendSynchronousRequest in a GCD block.